jackbauer
off to a rocking start
Member since December 2008
Posts: 1
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Post by jackbauer on Dec 15, 2008 17:59:26 GMT -5
After a successful 90, 120 & 600 grit stages I loaded up the Polish stage with a 12# tumbler about half full of stones, about 3/4 of a pound of pelletts, water just below line of stones and the right amount of polish. 8 days later and many of the stones in the load look cracked, chipped and like they have been beat up.
Where did I go wrong and how should I proceed here? Go ahead to next step with some walnut shell and finer polish? Backup and re-do another step?
I'm kind of lost on this one...
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Sabre52
Cave Dweller 
Me and my gal, Rosie
Member since August 2005
Posts: 20,496
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Post by Sabre52 on Dec 15, 2008 18:17:42 GMT -5
Jack: Assuming the problem is not a contamination problem where grit was left over from the previous stages or a problem where you have harder tougher stones mixed with more fragile materials, I would guess it's the larger multi-sided barrels. The twelve pound barrels with their multiple sided form seem to have a tendency to drop the stones against each other pretty darn hard in the thinner slurry of the polish stage causing chipping. To prevent this you have to have lots of various sized stones to prevent the larger stones from whacking together too hard and a pretty darn full barrel ( 3/4 full or more) and lots of plastic pellets. I was still having chipping problems in the 12 pounder during polish stage so went to using the round sided four pound barrels of the Lortone 33b for polish and prepolish. Action is much gentler in the round sided barrels and this solved my problem. I'd suggest checking the barrels to make sure you've no cross contamination between loads, make sure the loads are homogeneous hardness-wise, and making sure the barrel is well filled with lots of small stuff to help cushion the larger stones.....Mel
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Post by Hard Rock Cafe on Dec 15, 2008 20:26:33 GMT -5
I agree with Mel.
Chuck
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